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electric-fault-location
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A new algorithm for fault location on transmission lines by optimal PMU placement
, Article International Transactions on Electrical Energy Systems ; Volume 25, Issue 10 , 2015 , Pages 2071-2086 ; 20507038 (ISSN) ; Salehi Dobakhshari, A ; Ranjbar, A. M ; Tayebi, A ; Sharif University of Technology
John Wiley and Sons Ltd
2015
Abstract
In this paper, the problem of placing a minimum number of phasor measurement units (PMUs) in a transmission system is considered so that faults on all lines of the network can be diagnosed and located irrespective of their locations. For this purpose, a PMU placement algorithm is applied to calculate the required data for impedance-based fault location of any fault line in the network, achieving the full potential of the circuit laws throughout the system. Another algorithm is then proposed to compute the voltage and current values of the fault line for fault-location purposes. Moreover, as many networks are already equipped with PMUs, the proposed algorithm makes it possible to locate...
Optimal placement of sectionalizing switch considering switch malfunction probability
, Article IEEE Transactions on Smart Grid ; 2017 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Safdarian, A ; Sharif University of Technology
Abstract
Sectionalizing switches (SSs) are often presumed to function fully reliable. However, SSs are exposed to have some malfunctions, whereby undermining their ability to improve service reliability. This study presents a model to integrate SS malfunction probability into SS placement problem. The model aims to minimize the total SSs costs as well as customers interruption cost. The proposed model is formulated in mixed integer programing (MIP), which can be easily solved via several available solvers and gain global optimal solution. The proposed model indicates the extent to which the placement problem is affected by uncertainty associated with SSs functionality, and how not considering SSs...
Deployment of fault indicator in distribution networks: a MIP-based approach
, Article IEEE Transactions on Smart Grid ; Volume 9, Issue 3 , May , 2018 , Pages 2259-2267 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Safdarian, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Fault indicator (FI) plays a crucial rule in enhancing service reliability in distribution systems. This device brings substantial benefits for fault management procedure by speeding up fault location procedure. This paper intends to develop a new optimization model to optimally deploy FI in distribution systems. The proposed model aims to consider a tradeoff between the total customer interruption cost and FI relevant costs, including capital investment, installation, and maintenance costs. As the main contribution of this paper, the problem is formulated in mixed integer programing, which guarantees global optimum solution achieved in an effective runtime. Moreover, the model takes...
Optimal placement of sectionalizing switch considering switch malfunction probability
, Article IEEE Transactions on Smart Grid ; Volume 10, Issue 1 , 2019 , Pages 403-413 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Safdarian, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Sectionalizing switches (SSs) are often presumed to function fully reliable. However, SSs are exposed to have some malfunctions, whereby undermining their ability to improve service reliability. This paper presents a model to integrate SS malfunction probability into SS placement problem. The model aims to minimize the total SSs costs as well as customers interruption cost. The proposed model is formulated in mixed integer programing, which can be easily solved via several available solvers and gain global optimal solution. The proposed model indicates the extent to which the placement problem is affected by uncertainty associated with SSs functionality, and how not considering SSs...
Optimal placement of sectionalizing switch considering switch malfunction probability
, Article IEEE Transactions on Smart Grid ; Volume 10, Issue 1 , 2019 , Pages 403-413 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Safdarian, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Sectionalizing switches (SSs) are often presumed to function fully reliable. However, SSs are exposed to have some malfunctions, whereby undermining their ability to improve service reliability. This paper presents a model to integrate SS malfunction probability into SS placement problem. The model aims to minimize the total SSs costs as well as customers interruption cost. The proposed model is formulated in mixed integer programing, which can be easily solved via several available solvers and gain global optimal solution. The proposed model indicates the extent to which the placement problem is affected by uncertainty associated with SSs functionality, and how not considering SSs...
A novel GA-based High-Level Synthesis technique to enhance RT-level concurrent testing
, Article 14th IEEE International On-Line Testing Symposium, IOLTS 2008, Rhodes, 7 July 2008 through 9 July 2008 ; 2008 , Pages 173-174 ; 9780769532646 (ISBN) ; Aminzadeh, S ; Safari, S ; Navabi, Z ; Sharif University of Technology
2008
Abstract
This paper presents an efficient High-Level Synthesis (HLS) approach to improve RT-Level concurrent testing. The proposed method used for both fault detection and fault location. At first the available resources are used in their dead intervals to test active resources for fault detection, and then some changes are applied to the RT-Level controller to locate the faults. The fault detection step is based on a genetic algorithm (GA) search technique. This genetic algorithm is applied to the design after high level synthesis process to explore the test map. The proposed method has been evaluated based on dependability enhancement and area/latency overhead imposed to different benchmarks after...
A closed-form solution for transmission line fault location using local measurements at a remote substation
, Article Electric Power Systems Research ; Volume 111 , June , 2014 , Pages 115-122 ; ISSN: 03787796 ; Ranjbar, A. M ; Sharif University of Technology
Abstract
This paper presents a novel approach for fault location of overhead transmission lines by voltage and current measurements in a remote substation. The method is applicable when not all of the transmission lines in an area are equipped with fault-locators, although there may be a critical substation (CS) in the area equipped with a digital fault recorder (DFR). In the proposed method, the circuit equations of the network are used to find the transfer function between the fault location and each voltage and current measurement in the CS. Next, two auxiliary variables are defined to transform the nonlinear fault location estimation problem into a linear least squares problem. A closed-form...
A novel method for fault location of transmission lines by wide-area voltage measurements considering measurement errors
, Article IEEE Transactions on Smart Grid ; Volume 6, Issue 2 , 2015 , Pages 874-884 ; 19493053 (ISSN) ; Ranjbar, A. M ; Sharif University of Technology
Abstract
Smart transmission grids are intended to utilize various measurements for enhanced operation. In particular, synchronized phasor measurements have found many applications in this context. This paper presents a linear weighted least-squares (WLS) method for fault location estimation of transmission lines by synchronized voltage measurements. The measurements may be taken from the faulted line terminals or buses far from the faulted line. The circuit equations of the network are used to find the transfer function between the fault location and each voltage measurement. Next, two auxiliary variables are defined to transform the nonlinear fault location estimation problem into a linear WLS...
Fault analysis on AC railway supply system
, Article 6th Annual International Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2015, 3 February 2015 through 4 February 2015 ; February , 2015 , Pages 567-572 ; 9781479976539 (ISBN) ; Mokhtari, H ; Zolghadri, M. R ; Khodabandeh, M ; Abazai, A ; Seyyedi Khakshani, R ; Mazaheri, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
A short circuit fault in an AC railway supply system could have undesired consequences; including high-amplitude current flow in the power path, the rail potential rise in the fault vicinity. This paper studies the problem of the rail voltage rise in Tehran-Karaj railway system by the use of a steady state circuit model for the AC autotransformer during a phase-to-ground fault. By using this model, all the currents and voltages of the system can be easily calculated for all possible short circuit fault locations. With the help of the derived analytical model, one can also predict the possible fault locations which may cause the protection system to operate. The estimation of the system...
Simultaneous placement of fault indicator and sectionalizing switch in distribution networks
, Article IEEE Transactions on Smart Grid ; 2018 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Safdarian, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Automation systems provide substantial improvement in service reliability through speeding up fault management procedure. However, this is at expense of high investments whose justification needs thorough cost/worth analyses. This paper introduces a mathematical model to optimally place automation system devices within distribution networks. The model establishes a trade-off between service reliability improvements and the relevant costs. Among different automation system devices, fault indicators and remote controlled switches are considered here. Also, the impact of manual switches is regarded since their number and location significantly affect the solution of the placement problem. The...
Limiting fault currents in wind power plants using superconductive shielded core reactors
, Article IEEE Power and Energy Society 2008 General Meeting: Conversion and Delivery of Electrical Energy in the 21st Century, PES, Pittsburgh, PA, 20 July 2008 through 24 July 2008 ; 2008 ; 9781424419067 (ISBN) ; Salehfar, H ; Varahram, H ; Sharif University of Technology
2008
Abstract
In this paper we investigate the effects of superconducting shielded core reactor (SSCR) on the operation of induction generators. Large number of induction generators used in wind power plants generally increase the short circuit current level of the system. The reason is that they provide parallel reduced-impedance paths for the fault currents. Taking advantage of SSCR in wind power plants allows for using these generating units in large numbers with no concerns about the system fault current increments. The study is performed on a test system using the conventional model of an induction generator and a new effective model for SSCR based on its shielding behavior. Mathematical equations...
Secure steganography using Gabor filter and neural networks
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Volume 4920 LNCS , 2008 , Pages 33-49 ; 03029743 (ISSN); 3540690166 (ISBN); 9783540690160 (ISBN) ; Zahedi Kermani, Z ; Sharif University of Technology
2008
Abstract
The main concern of steganography (image hiding) methods is to embed a secret image into a host image in such a way that it causes minimum distortion to the host; to make it possible to extract a version of secret image from the host in such a way that the extracted version of secret image be as similar as possible to its original version (this should be possible even after usual attacks on the host image), and to provide ways of embedding secret images with larger size into a given host image. In this paper we propose a method that covers all above mentioned concerns by suggesting the idea of finding from an image data base, the most suitable host for a given secret image. In our method,...
Reliability enhancement in switching substations using fault current limiters
, Article 2006 9th International Conference on Probabilistic Methods Applied to Power Systems, PMAPS, Stockholm, 11 June 2006 through 15 June 2006 ; 2006 ; 9171783520 (ISBN); 9789171783523 (ISBN) ; Fotuhi Firuzabad, M ; Sidhu, T. S ; Sharif University of Technology
2006
Abstract
Power system equipments are normally designed for a specific system and load situation. This situation could change significantly as a result of the system expansion or aging. Among the system equipments, circuit breakers are more sensitive to the system expansion and they must be able to isolate the faulty components if a fault occurs. As the system load increases in the future, the power network must be expanded. In this situation, either the switching equipments must be replaced in order to be able to respond to the new fault current or the fault current must be limited to the interrupting capability of the existing circuit breakers. Application of Fault current Limiters (FCL) serves as a...